This invention relates to fasteners of the kind used to attach an item to, for example, a concrete surface, and in particular to fasteners that have a threaded member about which a high strength bonding agent is poured to form an anchor molded in situ.
In the past, relatively heavy items, such as permanent concrete barriers for dividing highway lanes, or rails for railroads held to concrete ties, were held in place by bolts or fasteners embedded in the concrete surface. However, because no provisions had been made for facilitating the simple and quick removal of such bolts or fasteners, it was often necessary to cut or burn off the bolt or fastener when it was necessary or desirable to remove or replace the barrier or rail.
In the applicant's previous U.S. application Ser. No. 521,111, filed Aug. 8, 1983 now abandoned, and entitled Anchor and Bolt, Method of Making, and Method of Securing by Same, fasteners are described that allow their removal from the hole in which they are embedded. These fasteners include a threaded shaft for location in a hole formed in the concrete or other surface, a head or other fastening part for securing the member to be affixed to the threaded shaft, and a two part grout or securing mixture that hardens in the hole about the threaded shaft to mold female threads engaging the male threads of the shaft. The threaded shaft may be coated with a release agent permitting the fastener to be backed out of the hole at some later time.